Positioning device for shifting gears in a transmission having an output component capable of two types of motion

ABSTRACT

A positioning device for an output component for automatically shifting gears of a motor vehicle transmission that undergoes two types of movements comprises a plurality of drives. The movement of each drive can be transmitted via a transmission mechanism to the output component. A first drive causes the output component to undergo movement of a first type, and a second drive causes the output component to undergo movement of a second type. The first drive is connected to a sliding element. The sliding element is axially fixed, but movable in the circumferential direction relative to the output component. The second drive is rotatably fixed, but axially movable output component.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a positioning device which moves anoutput component to a position using two separate types of motion. Morespecifically, the present invention relates to a positioning device forautomatically shifting gears in an transmission of a motor vehicle.

2. Description of the Related Art

According to DE 43 11 855 A1, a positioning device is known forpositioning a gearshift lever shaft of a transmission of a motor vehicleby using two drives for two separate types of motion. In thispositioning device, a first drive is arranged vertically relative to asecond drive. As FIG. 19 of that reference shows, the twisting orrotating of the gearshift lever shaft is produced by the first drive.The first drive linearly drives a gear rack, which engages a gear wheel.The gear wheel is fixedly connected to the gearshift lever shaft. Anaxial sliding of the gearshift lever shaft is effected by the seconddrive. To transmit the sliding movement, the second drive is activelyconnected to the gearshift lever shaft, so that the linear movement ofthe second drive is transmitted directly to the gearshift lever shaft.

Because of this sliding movement, the gear wheel that is fixedlyconnected to the gearshift lever shaft to transmit the rotary movementmust be long enough axially to ensure that the gear rack and the gearwheel remain engaged throughout the entire linear movement of thegearshift lever.

A problem with this transmission mechanism, is that the teeth of thegear wheel are constantly engaged with the teeth of the gear rack andrub against each other when the gearshift lever shaft is shifted. Thiscauses a heavy stress on the gear teeth. The teeth become worn,increasing the play between the engaged teeth. Particularly whenpositioning devices for positioning a gearshift lever shaft of atransmission are used, operability must be ensured for many shiftingprocedures. For this reason, the transmission mechanism described aboveis unsuitable for use in positioning the gearshift lever shaft of atransmission.

SUMMARY OF THE INVENTION

It is an object of the present invention provide a positioning devicewhich can move an output component through two different types ofmotions that is both compact and results in low-wear of parts, therebyensuring operability of the positioning device over a long period ofuse.

In the present invention, the first drive is guidingly connected to asliding element that is movable in an axial direction relative to theoutput component, for transmitting linear movement in the axialdirection to the output component. In turn, the output component isconnected in rotation-proof but axially movable fashion to the seconddrive. When the second drive is operated, rotational movement istransmitted to the output component by the second drive. The two typesof movement can be transmitted separately to the output component. Theoutput component is embodied in such a way that the sliding element isnot disturbed when rotational movements of the output component areeffected by the second drive.

Both linear and rotary type drives can be used for the first drive andthe second drive. When two drives that work in the same manner are used,it is necessary, due to the aforementioned two types of movement on theoutput component, to use a transmission to convert one type of movementinitiated by the drives into the other type. It has proved advantageousto drive the sliding element by a rotary drive. A drive of this type andthe sliding element are actively connected, for example, via atransmission element that converts the rotational movement of the driveinto a linear movement. To permit the smallest possible drive to beused, it is advantageous to provide a transmission element that acts asa reduction gear. One method of converting rotational linear motion tolinear motion is the use of a crank gear. To set different axialpositions of the output component, different positions that areassociated with the desired axial positions of the sliding element, andthus of the output component, are approached by the first drive. If thecrank drive were driven in one direction only, then two crank gearpositions would be associated with each axial position of the slidingelement. For unambiguous association, the crank gear is thereforepreferably driven in oscillating fashion.

A gear rack is another possible transmission element that can beprovided for converting a rotary movement into a linear movement. Thegear rack is driven linearly by means of the output element of the firstdrive. When a gear rack is used as a transmission element, it isadvantageous for the gear rack to be embodied as a single part with thesliding element. This transmission element represents an especiallysimple and economical construction. Very little structural space isrequired by the gear rack, and this is advantageous for a compactdesign.

The use of a cam gear as a transmission element has also provedadvantageous. The cam gear can have plateaus, slightly elevated in theradial direction, each of which is associated with a particular shiftposition of the sliding element. In this way, the sliding element andthus the output component can be set very accurately, for example, tothe shift positions associated with the channels of the motor vehicletransmission to which the output component is connected.

Another embodiment of the present invention includes a reset springurging the sliding element against the transmission element, the slidingelement is deflected against the force of the reset spring by means ofthe drive. Such reset springs make it possible, first of all, to keepthe sliding element and the gear in active connection by means of forcelocking, and secondly, to produce a return movement of the slidingelement by the action of the reset spring upon said element. For thispurpose of the return movement, it is necessary that the drive beshifted into a free-wheeling state.

The sliding element is mounted in a sleeve, which has an openingextending parallel to the sliding direction. This opening is penetratedby a radial projection of the sliding element, and the projection isconnected to the output component. The provision of this sleeve for thepurpose of mounting reduces the load on the sliding element and preventswear from friction. The smooth surfaces of the sleeve and slidingelement slide against each other. The sleeve surrounds the slidingelement, so that a compact design is achieved. It is preferable for theopening extending in the slide direction to be just large enough in thecircumferential direction that the radial projection of the slidingelement slides in the opening in this direction without play. As aresult, the radial projection of the sliding element is supported by theshape of the opening extending in the sliding direction, which helps torelieve stress on the sliding element.

In another embodiment, a lifting magnet is used as the first drive. Thelifting magnet is especially suitable for setting the desired channelposition, the adjusting of which requires less force than engaging agear. It has proved advantageous to select the different channels by asliding movement of the output component, because the lift movementproduced by the lifting magnet can then be transmitted to the slidingelement. When a transmission is used, however, it is also possible touse the lifting magnet for channel selection by a rotational movement.

To establish the connection of the second drive to the output component,a gear wheel is rotatably mounted on the sleeve. Suitable mountingminimizes the friction force that acts during a rotational movement. Thegear wheel is mounted in rotation-proof but axially movable fashionrelative to the output component. The gear wheel is fixed in the axialdirection of the sliding element, relative to the second drive, so thatno wear occurs on the teeth in the axial direction.

To minimize the structural area required, a segmental gear wheel isprovided for connecting the second drive to the output component. Theangular area of the segmental gear wheel is adjusted to correspond tothe rotational angular area requirements of the output component.

In an advantageous further development, a compensation spring isassociated with the second drive. In a rest position of the seconddrive, the compensation spring has a maximum prestress. When thecompensation spring is deflected from this rest position, the torque ofthe drive is reinforced by the relaxation of the spring. The use of sucha compensation spring makes it possible to support the engaging of agear. Engaging a gear requires considerable resistance because of thesynchronization work that must be performed. Since the compensationspring reinforces the second drive, a low-power drive is used. When anengaged gear is taken out of gear, no synchronization work must beperformed, so that support by the compensation spring is not needed.However, the power of the second drive must be selected in such a waythat the compensation spring again has the maximum prestress at the restposition. The rest position, in which the compensation spring has themaximum prestress, is associated with the neutral position of thegearshift lever shaft.

It has also proved advantageous for the drive or drives to have overloadprotection. This overload protection can be activated in the event offaulty control at the drive to prevent the transmission or continuationof the drive movement of a transmission element when a stop associatedwith this transmission element is reached. When the drive is an electricmotor, for example, the drive is thus protected against an overload thatcould lead to overheating of the electric motor. Furthermore, themechanical load of the components approaching or at a stop is reduced,preventing an excessive mechanical load that could lead the componentsto fail.

It has proved advantageous to provide a slip clutch as the overloadprotection. Such slip clutches can be integrated into an electric motor.When a stop is reached, the slip clutch is activated by the continueddrive in the prevailing direction of movement. Sensors for detecting themovement initiated by the electric motor are advantageously arrangedafter the slip clutch, so that the actual activating movement andposition are detected.

In a further embodiment the overload protection has elastic elements.When predetermined deflection positions are exceeded, these elasticelements undergo elastic deformation, counter to the force initiated bythe drive, for the purpose of absorbing the movement of the transmissionelement. Maximum deflection in a prevailing movement direction cantherefore occur only in a damped form of movement.

In a further embodiment of the present invention, a single positioningdrive transmits two types of movement to the output component. A shiftmechanism is used for shifting between the two types of motion. As aresult, the costs and structural area for a second drive for activatingoperate the output component are saved. A shift drive for shifting theshift mechanism is required. However, a drive with very low power andthus an extremely compact design suffices as the shift drive.

The shift mechanism includes a locking element. The locking elementblocks one of the two types of movement, so that the output componentcan be driven by the positioning drive only in the non-blocked type ofmovement. The locking element has a first claw, which engages into afirst depression of the output component without play in the axialdirection for the purpose of locking the output component. As a result,the output component is blocked against sliding movements by the firstclaw. The locking element also has a second claw, which engages into asecond depression of the output component without play in thecircumferential direction for the purpose of locking the outputcomponent against movement around its rotational axis.

The first claw has associated with it a plurality of depressions, andone channel of the transmission connected after the output component isdefined by each depression.

A large active torque causes a gear to be engaged quickly. It has beenfound advantageous for the second claw to always remain in the seconddepression. To release the lock, the second claw can be moved into aposition in which the second depression is larger, in thecircumferential direction, than the second claw. This enlargement of thesecond depression permits the rotational movement of the outputcomponent.

In another embodiment, the second depression is embodied in the shape ofa gap, whereby, for the purpose of allowing rotational movement, thesecond claw is positioned onto the position of the rotational axis ofthe output component. In this embodiment, as soon as the second claw ispositioned in a position that deviates from the rotational axis of theoutput component, the output component is blocked against rotationalmovements. This makes it especially simple to shift between the movementtypes without an overlap between them. The output component is alwaysexclusively driveable in the direction of one movement type only, i.e.,rotary or linear.

The positioning drive is connected to the output component of thepositioning device via a helical gearing. This helical gearing allowsboth a rotary and a linear movement to be simply transmitted to theoutput component of the positioning device. The transmission known fromDE 42 38 368 A1 has proved to be especially suitable as thetransmission.

The use of electric motors that are available as economical standardcomponents as the drives has proved to be especially advantageous. Suchelectric motors are rotary driven. The power required for theiroperation can be taken from a generator driven by the internalcombustion engine of the vehicle. In contrast, hydraulically-drivenpositioning devices have the disadvantage that a separate hydraulicsystem, which includes a pump, a pressure storage device and a pluralityof valves, must be provided to operate the positioning device. The costof providing the required hydraulic power is therefore considerable. Inaddition, due to the leakage always found in hydraulic systems, theenergy requirement is substantially greater than in an electricalsystem.

A further advantage of using electric motors is that the powerconnection lines are simple to run and require little space.

In an especially advantageous further development, the positioning driveis connected to a flange to be connected to the transmission. The flangeserves to accommodate auxiliary elements that permit further functions.The flange is embodied in such a way as to close the opening providedfor the gear-shift lever to pass through in a manually shifted vehicle.As a result, the actuator can be used without any modification to thegear housing being required. In addition, a closeable aperture for theinflow and outflow of transmission oil can be provided in the flange, ascan apertures for sensors. It has proved advantageous to detect thetemperature of the transmission or its environment, so that the increasein force required to engage a gear as the temperature drops can be takeninto account in controlling an automatic shift process. It is alsopossible to integrate a sensor for detecting the main gearshaft speed,which is used in many vehicles for control purposes (e.g., EKS). It isadvantageous to arrange the auxiliary devices centrally on the flange,so that the required incoming and outgoing lines can be run to theflange in bundles, which is advantageous for manufacture.

At least one drive includes a device that allows the manual adjustmentof the output component of the drive. This makes it possible, when thereis a disabled vehicle in which the electronics system has failed andwhich is in gear, to take the vehicle out of gear manually. Thetransmission is shifted to a no-load state and the vehicle can be towedas usual by a driveable vehicle. However, before the disabled vehicle istaken out of gear, its hand brake must be activated, so as to preventthe vehicle from rolling when taken out of gear.

It is also possible for both drives to be equipped with a device formanual operation, by means of which the drives can be deflected in themovement direction driven during normal operation. It thus becomespossible to place the vehicle into gear manually, particularly into astart-up gear.

It has proved advantageous for the end of the motor shaft of the drivethat faces away from the output component to be equipped with aspecially shaped profile. Engaging into this profile is acounter-profile of a positioning element, preferably a tool that iscarried in the vehicle. This device can, however, also be arranged atanother location. In some circumstances, it is advantageous to select aneasily accessible predetermined location, so that under certaincircumstances a transmission can be required for a power turn.

The output component can be placed into the desired position, preferablythe idle position, by means of manual drive. The desired position can beidentified by the positioning force that must be expended. For example,putting a vehicle into gear and taking it out of gear requires moreforce than adjusting the output element in the idle range. The idleposition can thus be identified by easy manual operation.

Other objects and features of the present invention will become apparentfrom the following detailed description considered in conjunction withthe accompanying drawings. It is to be understood, however, that thedrawings are intended solely for purposes of illustration and not as adefinition of the limits of the invention, for which reference should bemade to the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, wherein like reference numerals denote similar elementsthroughout the several views:

FIG. 1 is an elevational view of the positioning device of the presentinvention with a crank gear, perpendicular to the longitudinal axis ofthe positioning device;

FIG. 2 is a sectional view of the positioning device of FIG. 1 alongline II--II;

FIG. 3 shows the positioning device of FIG. 1 with a gear rack;

FIG. 4 shows the positioning device of FIG. 1 with a cam gear;

FIG. 4a shows the cam gear of FIG. 4;

FIG. 5 is a sectional view of the positioning device of FIG. 4 alongline V--V;

FIG. 6 shows the positioning device of FIG. 1 with a lifting magnet;

FIG. 7 shows a lifting magnet arrangement for producing a swivel motion;

FIG. 8 is a side view of the lifting magnet of FIG. 7 viewed from theright;

FIG. 9 shows the positioning device of FIG. 1 with a compensation springon the second drive;

FIG. 10 is a sectional view of the positioning device of FIG. 9 alongline X--X;

FIG. 11 is an elevational view of another embodiment of the positioningdevice of the present invention with a shift mechanism and only onepositioning drive and one locking element;

FIG. 11a is a sectional view of the positioning device of FIG. 11 alongline A--A;

FIG. 12 is a sectional view of the positioning device of FIG. 11 alongLine XII--XII;

FIG. 13 shows a rotary locking element;

FIG. 14 shows another embodiment of the rotary locking element of FIG.13;

FIG. 15 shows an overload protection with elastic elements;

FIG. 16 shows an overload protection with prestressed spring elements;

FIG. 17 shows a segmental gear wheel with a stop absorption as overloadprotection;

FIG. 18 shows another embodiment of the segmental gear wheel with a stopabsorption;

FIG. 19 is a sectional view of the segmental gear wheel of FIG. 18 alongline IV--IV; and

FIG. 20 is a perspective view of the positioning device of the presentinvention with a flange and auxiliary elements.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

Referring to FIGS. 1 and 2, the basic structure of a positioning device1 is described. A positioning device 1 includes a first drive 3, whichis connected via a crank gear 14 to a sliding element 7. The slidingelement 7 is mounted in a sleeve 23 and has at its end a radialprojection 27, which penetrates an opening 25 provided in the sleeve 23into a radial gap 28, running along a circumferential direction of anoutput component 9. The opening 25 in the sleeve 23 is a gap 26 runningin the axial direction.

The output component 9 also has an axial opening 35, into which engagesan axial projection 33 of a segmental gear wheel 31 mounted on thesleeve 23. The segmental gear wheel 31 is engaged via toothing with agear rack of a second drive 5 that acts via a reduction gear 6.

The function of the positioning device 1 is described in what follows.This positioning device 1 can be used for the automatic positioning of agearshift lever shaft of an automobile transmission, which here is theoutput component 9 of the positioning device 1. The first drive 3operates with an oscillating movement and drives a crank gear 14. Thecrank gear 14 is connected to the sliding element 7, which carries out alinear movement. The linear movement of the sliding element 7 istransmitted to the output component 9 via the radial projection 27,whereby the sliding element 7 slides in the sleeve 23 wherein it ismounted. The radial projection 27 of the sliding element 7 is supportedin the circumferential direction by the opening 25 running in the axialdirection in the sleeve 23. The linear movement transmitted to theoutput component 9 serves to engage the desired channel of thetransmission. Gear selection is carried out by a rotational movement ofthe output component 9 (the gearshift lever shaft). The requiredrotational movement is initiated by the second drive 5. The second drive5 drives the segmental gear wheel 31. The rotational movement of thesegmental gear wheel 31 is transmitted to the output component 9 via anaxial projection 33, which engages an axial opening 35 on the outputcomponent 9. The output component 9 and the segmental gear wheel 31 areaxially movable relative to one another, so that a linear movementtransmitted to the output component 9 has no influence on the positionof the segmental gear wheel 31. The sliding element 7 is also connectedin rotatable fashion to the output component 9, so that a rotationalmovement of the output component 9 initiated by the second drive 5 hasno influence on the sliding element 7. Greater force is required toengage the desired gear than for channel selection, so that a morepowerful drive is necessary for this purpose. So that the smallest drivepossible can be used, this drive can be equipped with a reduction gear6.

The first and second drives 3 and 5 are connected fixedly to a housing8, which in turn is connected fixedly with a flange (such as flange 117on FIG. 20) on the gearbox, which closes the opening formerly providedfor a manual gear-shift lever (stick shift) to pass through. The flangeand the housing 8 can also be simply embodied as a single piece.

The positioning device 1 shown in FIG. 3 for positioning the gearshiftlever shaft 10 (which is the same part as output component 9)corresponds substantially to that described in reference to FIG. 1. Thedifference is that instead of the crank gear 14, a gear rack 15 isprovided. This gear rack 15 is driven by the first drive 3 in a linearmovement, which is transmitted to the sliding element 7. In the exampleshown, the sliding element 7 and the gear rack 15 are embodied as asingle piece. An output element 4 of the first drive, which works inrotary fashion, engages into the gear rack 15. The rotation of theoutput element 4 of the first drive 3 moves the gear rack 15 in theaxial direction.

FIGS. 4 and 5 show a positioning device in which a cam gear 17 is usedwith the first drive 3. The rotating output element 4 of the first drive3 engages a gear wheel 16, which is fixedly connected to a cam 18 or isembodied with the latter as one piece. The end of the sliding element 7runs to this cam 18, and the sliding element 7 is connected to the cam18 in a force-locking manner by a reset spring 19. However, it is alsopossible to establish the active connection between the cam 18 and thesliding element 7 via a groove-claw connection.

FIG. 4a shows the cam 18 with several plateaus 24. Each of theseplateaus 24 is associated with one channel.

FIG. 6 shows a positioning device 1 that has a lifting magnet 21 inplace of the first drive 3. The end of the sliding element 7 extendsinto the lifting magnet 21. The opposite end, which has an axialprojection 150, is acted upon by a reset spring 19. When current isprovided to the lifting magnet 21, the sliding element 7 is movedlinearly against the force of the reset spring 19 depending upon theapplied current or voltage. Channel selection is carried out by means ofthe lifting magnet 21. If channel selection is carried out by arotational movement in a transmission connected after this, as shown inFIGS. 7 and 8, then a driven part 22 of the lifting magnet 21 acts upona reversing lever 30; which is fixedly connected to the gearshift levershaft 10. The reset spring 19, which ensures a force-locking connectionbetween the reversing lever 30 and the driven part 22 of the liftingmagnet 21, is provided on the side opposite to the lifting magnet 21.When the lifting magnet 21 is activated, its driven part 22 is deflectedagainst the reset force of the reset spring 19 that acts upon thereversing lever 30. The positioning device 1 shown in FIGS. 9 and 10corresponds substantially to the positioning device shown in FIGS. 1 and2, but has, in addition, a compensation spring 36, which is associatedwith the segmental gear wheel 31. The compensation spring 36 is fixedlyconnected to the segmental gear wheel 31, which can be rotary-driven bymeans of the second drive 5, and rests against the housing 8 of thepositioning device 1. The compensation spring 36 has maximum prestressin the middle position of the segmental gear wheel 31. Upon deflectionof the segmental gear wheel 31 by the second drive 5, the torquesupplied by the latter is reinforced by the relaxation of thecompensation spring 36. The process of engaging the selected gear isthus supported and speeded up. The segmental gear wheel 31 is againbrought to the middle position by means of the second drive 5. Thecompensation spring is thereby prestressed again. The force needed forthis purpose is supplied by the second drive 5. This movement directionis associated with taking out of gear a gear that was previouslyengaged. Less force is needed to take out a gear than to engage a gear,because no synchronization work must be performed in the transmission.For this reason, the provision of the compensation spring 36 allows thesecond drive 5 to be used with lower power for engaging a gear.

FIGS. 11 to 14 show a positioning device 1 that has only one positioningdrive 2. This positioning drive 2 serves, via a helical gearing 53, todrive a gearshift lever shaft 10 (the output component 9) of thepositioning device 1. The helical gearing 53 has a spindle 54 that isdriven by the positioning drive 2. The end of the spindle 54 is mountedin the housing 8 and supported by bearing 63. The spindle 54 engages adriven element 55, which is fixedly connected to the gearshift levershaft 10. The driven element 55 and the gearshift lever shaft 10 canalso be embodied as a single piece.

The gearshift lever shaft 10 has associated with it a shift mechanism49, which encompasses a locking element 50. This locking element 50 isarranged at an end 67 of the gearshift lever shaft 10 facing away fromthe transmission of the vehicle it is mounted on. The locking element 50includes a shift drive 59 and a latching element 65, which has a firstclaw 39 and a second claw 41. The first claw 39 has associated with itfirst depressions 43, and the second claw 41 has associated with it asecond depression 45. The first depressions 43 are embodied axiallyoffset relative to one another and run in the circumferentially on theouter circumference of the gearshift lever shaft 10. The seconddepression 45 is arranged at the end 67 of the gearshift lever shaft 10.In this example, the second depression is embodied in the shape of agroove and intersects the rotational axis 47 of the gearshift levershaft 10.

By activating the shift drive 59, the latching element 65 can be movedinto different operating positions. In this manner, the type of movementon the gearshift lever shaft 10, i.e., axial sliding movement orrotational movement, can be established. In a first operating position,which is shown in FIG. 11, the first claw 39 engages into one of thefirst depressions 43, as a result of which the gearshift lever shaft 10linear movement is prevented. When the first claw 39 is latched in, thesecond claw 41 is placed onto the position of the rotational axis 47 ofthe gearshift lever shaft 10, allowing the latter to rotate about therotational axis 47 and the claw 41. Consequently, when spindle 54 isrotated by the positioning drive 2, rotational movement of the gearshiftlever shaft 10 is produced.

In a second operating position, the first claw 39 is withdrawn from thefirst depressions 43. The second claw 41 is located in a position thatdiffers from that of the rotational axis 47 of the gearshift lever shaft10. In this position, the second claw 41 is engaged with the seconddepression 45 without play in the circumferential direction. Whenspindle 54 is rotated by the positioning drive 2, a linear movement istransmitted to the gearshift lever shaft 10, because the helical gearing53 of spindle 54 has a slope in the axial direction.

FIG. 12 shows a sectional view of the shift drive 59 and the first claw39 engaged into one of the first depressions 43. The rotation of thegearshift lever shaft 10 is permitted, when there is axial locking, bythe extension of the first depression 43 in the circumferentialdirection.

FIGS. 13 and 14 show partial views of further examples of lockingelements 50. To block the rotational movement of the gearshift levershaft 10, these locking elements 50 are equipped with a device unlikethat in FIG. 11. In FIG. 13, the second depression does not intersectthe rotational axis 47 of the gearshift lever shaft 10. For this reason,the second depression 45, for the purpose of allowing rotary movement ona section of its radial extension, is embodied with an expansion in thecircumferential direction. In the operating position in which rotarymovements of the gearshift lever shaft 10 can be produced by means ofthe positioning drive 2, the second claw 41 is engaged with theexpansion of the second depression 45 at the position shown indashed-dotted lines in FIG. 13. The locking element shown in FIG. 14 hasa second claw 41 shaped like a trapezoid. This claw 41 is engaged withthe second depression 45, which is also shaped like a trapezoid. Theplay in the circumferential direction between the second claw 41 and thesecond depression 45 can be adjusted by the radial position of the claw41. If the second claw 41 and the second depression 45 are engagedwithout play, as shown in FIG. 14 in dashed lines, then the gearshiftlever shaft is blocked against a rotational movement.

FIG. 15 shows a section of the positioning unit. A design fortransmitting the movement initiated by the first drive 3 is shown. Thedesign shown differs from that in FIG. 1 in that FIG. 15 includes anoverload protection 69. The basic function described in reference toFIG. 1 remains unchanged.

The overload protection shown in FIG. 15 has elastic elements. Theseelastic elements are spring elements 77, 79, which are coaxially mountedover the sliding element 7. The spring elements 77 and 79 are in turncoaxially surrounded by the sleeve 23, which is used for mounting thesegmental gear wheel 31 (the segmental gear wheel is not shown in FIG.15). The spring elements 77, 79 are arranged at the respective ends inthe sleeve 23. The sliding element 7 is equipped with projections 85, 87that form radial support surfaces for the spring elements 77, 79. Theseradial projections 85, 87 serve to enlarge the diameter of the slidingelement 7, but only to such an extent that this diameter remains smallerthan the inner diameter 101 of the sleeve 23. The ends of sleeve 23 haveprojections 89, 91 formed by rings and pointing radially inward, each ofwhich constitutes a second support surface for the spring elements 77,79.

If faulty control of the drive 3 occurs and the sliding element 7 ismoved farther than normal in a deflected direction, then the projection87 of the sliding element 7, for example, comes into active contact withthe spring element 79. The kinetic energy of the sliding element 7 isconverted at least partially into deformation energy of the pressurizedspring element 79, and the sliding element 7 is slowed down. As aresult, the radial projection 27 is prevented from hitting the stop 88.

The design shown in FIG. 16 has the overload projection 69 with adifferent embodiment of stop absorption. This example has anintermediate sleeve 93, in which the spring elements 77, 79 arearranged. The spring elements 77, 79 are clamped in the intermediatesleeve 93. The sliding element 7 here is formed by the gear rack 15 andthe intermediate sleeve 93, and the stop absorption is integrated intothis sliding element 7. On the end facing away from the drive, theintermediate sleeve 93 has projections 95 directed radially inward,which constitute a support surface for a first spring element 79. Thefirst spring element 79 is placed into the intermediate sleeve. The gearrack 15, which has a projection 99 that runs radially and coaxially andforms support surfaces for the spring elements 77, is inserted. Thesecond spring element, which faces the drive 3, is slid onto the gearrack 15, and the intermediate sleeve 93 is closed at the end, e.g, byshrinkage of a closing ring 97. The spring elements 77, 79 are enclosedin the intermediate sleeve 93. Upon closing, the spring elements 77, 79can be prestressed in a predetermined manner by the axial insertiondepth of the closing ring 97. If soft springs are used, these areprovided with a prestress such that, under normal operating conditions,the springs will form a rigid connection between the gear rack 15 andthe intermediate sleeve 93. If the radial projection 27 hits a stop 88,then the kinetic energy of the gear rack 15 is at least partiallyconverted into potential energy of the pressurized spring element, and arelative movement begins between the gear rack 15 and the intermediatesleeve 93.

FIG. 17 shows a segmental gear wheel 31 equipped with stop absorption asthe overload protection. The maximum deflection angle of the segmentalgear wheel is limited on both sides by stops 105. The segmental gearwheel 31 is equipped at the level of the stops with an opening 103 toaccommodate spring elements 81, 83, which extend out over the limitingedges, which run in the radial direction, of the segmental gear wheel31. If faulty operation of the drive 5 occurs and the segmental gearwheel 31 is deflected farther than usual, then the spring elementarranged on the corresponding side, e.g., 81, comes into activeconnection with the stop 105 associated with this spring element. Thekinetic energy of the segmental gear wheel 31 is converted intodeformation energy of the pressurized spring element 81, as a result ofwhich the segmental gear wheel 31 can reach the stop only in deceleratedmovement form.

FIGS. 18 and 19 show a segmental gear wheel 31, which includes anoverload protection 69 with spring elements. The segmental gear wheel 31has an opening 109 to accommodate an inner segmental wheel part 107. Thesegmental gear wheel 31 and the inner segmental wheel part 107 areconnected via two spring elements 81, 83 arranged tangentially betweenboth sides of the inner segmental wheel part 107 and inner sides of thesegmental gear wheel 31. The inner segmental wheel part 107 is mountedrotatably on the sleeve 23, its rotatability being ensured by means of aslide bearing 111, and has an axial projection 33 engaging into the slotof the output component 9 (not shown in FIG. 18). The segmental gearwheel 31 is rotatably mounted on inner segmental wheel part 107,coaxially encompassing a partial section thereof. The spring elements81, 83 have a spring constant such that, given correct positioning ofthe drive 5, a rotation-proof connection is ensured between thesegmental gear wheel 31 and the inner segmental wheel part 107.

The function of this overload protection is described as follows: As theresult of faulty control of the drive 5, the inner segmental wheel part107 can strike one of the stops arranged in the transmission. When theinner segmental wheel part 107 reaches the stop, its further rotation isprevented. The drive 5 continues to drive the segmental gear wheel 31.The kinetic energy of the segmental gear wheel 31 is converted intodeformation energy of at least one of the spring elements 81, 83, and arelative movement begins between the inner segmental wheel part 107 andthe segmental gear wheel 31. If the springs of the spring elements 81,83 are fixedly connected to the inner segmental wheel part 107 on oneside and, at the opposite end, are connected fixedly to the segmentalgear wheel 31, then both spring elements 81, 83 absorb stress energywhen the inner segmental wheel part 107 reaches a stop, the first springelement being stretched and the other being compressed. Other possibleembodiments of stop absorptions for segmental gear wheels are known, forexample, from DE 195 25 840 C1.

FIG. 20 shows the positioning device 1 with a flange 117 to be connectedto a transmission. This flange 117 has an aperture 121 for the inflowand outflow of transmission oil. Another aperture for a speed sensor 125extends into the transmission to detect the main gearshaft speed isembodied as a further auxiliary element 119. In this example, atemperature sensor 127 extends only into the housing 8 of thepositioning device 1. However, it is possible to have this temperaturesensor 127 extend into the transmission through yet another aperture inthe flange 117 provided for this purpose. The temperature value istransmitted to a control device for controlling an automatic gearshift.Since the positioning force required to engage a gear increases as thetemperature decreases, the control device can position the drives takinginto account the temperature prevailing in the transmission. In thisexample, the drive 5 is equipped with a slip clutch 73. Such a slipclutch 73 can also be integrated into the drive housing or into theelectric motor 57. Furthermore, this positioning device is equipped witha plurality of sensors 129, 131 for detecting the positioning movementinitiated by the drives. The second drive 5 has, at its free end, amanual positioning device 133 for the manual positioning of the outputelement of the second drive 5. This manual positioning device 133 isrealized by equipping an end of the motor shaft 135 with a projectionengagable by a tool. This end of the motor shaft 135 is covered by acover element 139 in the motor housing of the second drive 5.

The function of the manual positioning device is required in thefollowing situations: When a vehicle is disabled while in gear and withan engaged clutch, it cannot be towed by a pulling vehicle; When theelectronic system fails, the driver is unable to set the transmissionposition; and When the vehicle is equipped with an EKS and the clutch isengaged, the driver is not able to shift into a non-loaded gear. Themanual positioning device is provided for these cases. The driver is nowable, by opening the hood and removing the cover element, to manuallyplace the transmission into a neutral position, in which the gear isshifted in loadless fashion, by manual operation of the motor shaft 135.The neutral position, here the idle position, is recognizable by thedriver by positioning forces to be applied. However, it is alsopossible, upon identifying the gear, to set an positioning manner forthe manual removal of the gear.

The invention is not limited by the embodiments described above whichare presented as examples only but can be modified in various wayswithin the scope of protection defined by the appended patent claims.

We claim:
 1. A device for positioning an output component for shiftinggears in a transmission of a motor vehicle using two types of movement,comprising:a housing; a sliding element having a longitudinal axisslidably mounted on the housing for movement along the longitudinalaxis; a first drive being mounted on the housing and operativelyconnected to the sliding element for moving the sliding element alongthe longitudinal axis; the sliding element being axially fixed to theoutput component such that the output component moves with the slidingelement along the longitudinal axis in a first of the two types ofmovement; the output component being movable in a circumferentialdirection relative to the sliding element; a second drive being mountedon the housing and operatively connected to the output component formoving the output component in a second of the two types of movement;the output component being axially movable and rotation-proof relativeto the second drive; a sleeve mounted on the housing; the slidingelement being slidably mounted in the sleeve; the sleeve having a recessextending along the sliding direction; and a radial projection of thesliding element penetrating the recess and being connected to the outputcomponent.
 2. The device of claim 1, wherein the first drive operates ina rotary movement and a transmission element connects the first drive tothe sliding element, the transmission element converting the rotarymovement of the first drive into a linear movement of the slidingelement.
 3. The device of claim 2, wherein the transmission elementcomprises a crank gear, and the crank gear is connected to the slidingelement.
 4. The device of claim 2, wherein the transmission elementcomprises a gear rack connected to the sliding element and engaged withan output element of the first drive.
 5. The device of claim 2, whereinthe transmission element comprises a cam gear connected to the slidingelement.
 6. The device of claim 2, further comprising a reset spring forurging the sliding element against the transmission element.
 7. Thedevice of claim 1, wherein the first drive further comprises a liftingmagnet; andthe lifting magnet operatively connected to a driven partconnected to the sliding element for moving the sliding element.
 8. Thedevice of claim 1, further comprising a gear wheel operativelyconnecting the second drive to the output component, the gear wheelrotatably mounted on the sleeve; andthe output component beingrotation-proof but axially movable with respect to the gear wheel. 9.The device of claim 1, further comprising a segmental gear wheeloperatively connecting the second drive to the output component, thesegmental gear wheel rotatably mounted on the sleeve; andthe outputcomponent being rotation-proof but axially movable with respect to thesegmental gear wheel.
 10. The device of claim 1, wherein the seconddrive further comprises a compensation spring; andthe compensationspring having a maximum prestress in a rest position of the drive suchthat when the drive is displaced from the rest position, the springreinforces, by relaxation, the torque supplied by the second drive. 11.The device of claim 1, wherein at least one of the first drive and thesecond drive further comprises an overload protection operativelyconnected to the at least one of the first drive and the second drivefor preventing the transmission of the drive movement of a transmissionelement when a stop associated with the transmission element is reached.12. The device of claim 11, wherein the overload protection comprises aslip clutch which is activated when a stop is reached by continueddriving of the transmission element in the prevailing movementdirection.
 13. The device of claim 11, wherein the overload protectioncomprises elastic elements that, when a preset deflection position isexceeded, experience deformation counter to the force initiated by theat least one of the first drive and the second drive for absorbing themovement of the transmission element.
 14. The device of claim 1, whereineach of the first drive and the second drive comprises an electricmotor.
 15. The device of claim 1, wherein the housing comprises a flangeto be connected to a transmission of a motor vehicle; andthe flange isoperatively connected to accommodate auxiliary elements for performingfurther functions.
 16. The device of claim 15, wherein one of theauxiliary elements comprises at least one aperture for the inflow andoutflow of transmission oil, the aperture further comprising a closingelement for selectively closing and opening the aperture.
 17. The deviceof claim 15, wherein the auxiliary elements comprise a temperaturesensor and a speed sensor for detecting the main gearshaft speed. 18.The device of claim 1, wherein at least one of the first drive and thesecond drive further comprises a manual device operatively connected tothe one of the first drive and the second drive for permitting a manualadjustment of the output component.
 19. The device of claim 1, whereinthe second drive comprises a manual device operatively connected formanually driving a motor shaft fixedly connected to an output element ofthe second drive.
 20. The device of claim 19, wherein the motor shaftcomprises a section, at one end, into which engages a correspondingsection of a positioning element used by the manual device.